Joining us now from the campaign trail in Ames, Iowa is Republican presidential candidate and former senator Fred Thompson.

And, Senator, welcome back to "FOX News Sunday."

REPUBLICAN PRESIDENTIAL CANDIDATE FRED THOMPSON: Thank you, Chris. Good to be with you.

WALLACE: You're getting headlines in the morning papers for some comments you made on the campaign trail yesterday. Let's take a look. You said, "I'd like to say I'm only consumed by very, very few things, and politics is not one of them."

Then you went on to say, "I'm not sure in the world we live in today it's a terribly good thing that a president has too much fire in his belly." Senator, don't voters want someone who really wants to be president?

THOMPSON: Well, Chris, what you just read is just another case of me being just as open and candid as I can possibly be when average citizens ask me questions in a public forum. And you add a little journalistic malpractice to that, and this is what you get this morning.

The latter part of that comment, for example, about my not being consumed with politics, was that I am consumed — the very next sentence, as a matter of fact — that I am consumed with the notion of what's going to happen to my kids, my grandkids and my country, and that that's why I was running for president.

But I was very — we had a long discussion from which they cherry-picked, of course, to try to make a little interesting story out of it, about the future of the country and why I was doing what I was doing, why my family was making the sacrifices they were making for me to be able to do this.

I've never been personally consumed. It's not a part of my identity — politics isn't, and never will be. I've said that I don't like every aspect of the way that people have to campaign nowadays in terms of process taking precedence over substance.

But I'm in the middle of a 50-town tour in the state of Iowa, working day and night. I think that pretty much speaks for itself.

WALLACE: Senator, let's look at the latest numbers out of Iowa. According to the Real Clear Politics average of recent polls from the state, you're running third, but a distant third, trailing Huckabee and Romney by more than 2-1.

If that's the way the world turns on Thursday night, is that good enough for you to get any bounce out of Iowa? How do you have to do there?

THOMPSON: No, that would not be good if that turns out to be that way. They've got an outlier poll in there that nobody really takes seriously. It's got me at about five or something. Then they put that in the mix.

But most of the polls that have been reliable in the past have me in the teens or the high teens, still third, but pretty close and showing movement.

And if you look at the latest national poll, the Rasmussen poll, I'm within, I think, six of the top. We're all kind of bunched together. So again, it depends on the polls that you're looking at.

But we have every reason to be optimistic. We've shown movement, and I think we're going to do better than that.

WALLACE: Well, you have a better sense of it than any of us. You're in that 50-town tour. How do you think you're going to do on Thursday night?

THOMPSON: That's the first time you've ever acknowledged that, Chris. I appreciate that.

WALLACE: Well, there's a first time for everything. How do you think you're going to do, sir?

THOMPSON: No, I do get that sense. Of course, everybody's rallying around their favorites now, but we're having overflow crowds and we're having great enthusiasm. And we're going to have great representation on caucus night.

I've just been coming up the middle, being steady, being consistent with my message and pointing out that my record of a strong conservative, common-sense conservative, is — it really stands out.

Background, as far as national security is concerned, and having served on the Intelligence Committee, traveled the world, including Pakistan — I met with Musharraf and other foreign leaders and I'm grounded and experienced in the matters that matter to us.

So while the others are fighting and squabbling and spending millions of dollars running ads against each other, I'm just steady, up the middle, and so far we've shown steady progress, so I have...

WALLACE: Well, Senator, let's talk about national security, and let's talk about the frontrunner, because after the tragic assassination of Benazir Bhutto, you took Governor Huckabee to task when he talked about wanting to bring the killers to justice. Let's take a look.

(BEGIN VIDEO CLIP)

MIKE HUCKABEE, PRESIDENTIAL CANDIDATE: The first thing I think you do is to try to make sure that we monitor closely who's behind it, who's responsible.

(END VIDEO CLIP)

(BEGIN VIDEO CLIP)

THOMPSON: People talk about rounding them up and, you know, bringing the perpetrators to justice. Well, that would be great, wouldn't it? But this is not a criminal investigation. This is a war.

(END VIDEO CLIP)

WALLACE: Senator, isn't it important to find the killers and bring them to justice?

THOMPSON: Well, of course it is, if that can be done. Probably can't be done. But we're losing sight of the bigger picture. This is a part of the global conflict that we're in.

We've had a war declared against us by radical Muslims, and this is a part of that picture, just as the Middle East is, just as what's going on in North Africa and other parts of Asia. We've seen it manifest in Europe. And we need to understand that.

This is not just a local isolated action. These people are willing to kill foreign leaders, as they've done in times past in Egypt and Afghanistan, and they're certainly more than willing to kill friends and allies of the West, which they want to bring down, allies of the United States of America.

And this is another part of that pattern and it reminds us of what we need to do and the kinds of things we need to do, the unity and strength we need to show, in order to battle these people wherever we have to.

WALLACE: Well, let me ask you, though, because there was an implicit criticism in what you said about Mike Huckabee. Straight out, do you think that Mike Huckabee is prepared to be commander in chief?

THOMPSON: Well, I'm not going to throw a — that kind of a large blanket over Mike or anybody else. I will say that people are going to have to make up their own minds. I'm not sure politicians are the best critics of their colleagues on matters like this.

I just say take a look at everybody. Take a look at the experience and what they're saying. I've been critical of Mike's statements before when he says close down Guantanamo and bring those people to the United States of America. Implicit in that is giving them habeas corpus rights and things of that nature — enemy combatants treated as American citizens.

When he says let's deal with Castro and things like that in the past, which I think he's changed his mind on now, I disagree with those things and I point out that we need someone who understands the nature of the world that we live in and someone that certainly does not fall into the Democratic mode of blame America first for all these problems that come around.

There was an apology issued by the governor after former Prime Minister Bhutto was killed. I think he later clarified that, but I was wondering what the rest of the world thought about one of our presidential candidates apologizing after a foreign leader was assassinated.

Those kinds of things are going to have to be weighed. And clearly, he doesn't have a lot of experience in these areas.

I'm more interested in his ideas now than what he's done or said in the past on these things, but his ideas now are not consistent with someone who understands the nature of the world that we live in and the challenges we're going to face.

WALLACE: Let me ask you about the other person who's leading you in the polls. Do you think Mitt Romney is prepared to be president and has a consistent record as a conservative?

THOMPSON: Well, that's two different questions. Clearly, as far as the conservative issue is concerned, he's changed his mind and he's changed his position on a lot of different things. Most of them have to do with basic conservative principles.

He went out of his way to point out that he was not to be affiliated with Reagan-Bush in times past, and now he quotes president Reagan at the drop of a hat.

So he's changed his basic philosophy with regard to a lot of things like taxes and the original immigration proposal, and I could go on and on as far as that's concerned.

Difficult to pin Mitt down as to exactly what he does fundamentally believe and which of those beliefs he would stick with through thick and thin in the future when the strong winds are blowing.

Now, as far as — it's not for me to judge a person's fitness. It's just objectively clear that Mitt does not have any foreign relation experience and doesn't have any experience with dealing with matters of national security.

He's got vast experience in the business community, been very successful, and I'm sure he's been a good manager. So all of us have things to bring to the table.

And I point out my background. I've had an opportunity to help cut taxes and pass welfare reform, balance the budget, fight for conservative judges. I had a 100 percent pro-life voting record. I was on the Intelligence Committee. I chaired an important committee dealing with some of these problems.

I was the Republican floor manager for the homeland security bill, which I like to think has had something to do with the fact we haven't been attacked again since September 11th. That's my background.

After I left the Senate, Condoleezza Rice asked me to chair an advisory board to her, to advise her on international security matters. So I do understand the nature of the world we live in and the challenges we face.

WALLACE: But, Senator, and you do point out that you have a considerable edge in foreign policy experience over Romney and Huckabee and Giuliani, but if voters are really looking at that, doesn't John McCain have an edge over you?

He's been at the center of every national security debate in this country for more than a decade.

THOMPSON: I can't argue with that. John has vast experience. He served on the Armed Services Committee for longer than I served in the Senate — no question about that.

I was able to serve in some areas that John did not serve in, but his overall service has been longer and he's been involved for a long time.

I think that we have to have someone of experience in that area, and someone with sound conservative principles, and someone who has been there consistently for a long period of time.

John and I have some honest disagreements with regard to some domestic issues. We've looked at things a little differently over the years on some important things, so that has to be figured into the mix also.

But if you're strictly talking about national security, you certainly cannot avoid the fact that John McCain has vast experience.

WALLACE: You talk about your service, particularly since you left the Senate, and one of your — you say one of the biggest foreign policy challenges is China.

In 2005, as an ex-senator, you were appointed by Congress to serve on a commission, the U.S.-China Economic and Security Review Commission. But during your two-year term, you attended only six of the 19 meetings of this panel, which monitors our economic and national security relationship with China. Senator, how come?

THOMPSON: Well, I conducted hearings there. I chaired some hearings that we had there. I had telephone conferences with them. They sent me materials. I read the materials that were there.

This was a voluntary commission to serve on. They were primarily interested in my ideas more than me sitting through hearings that might be domestic or foreign. My emphasis, my concern, was the Chinese military build-up.

Some of these economic-related issues I was not as concerned with. And I was working two full-time jobs. This was a non-paying position, a voluntary position, and I was working a couple of other jobs to earn my livelihood.

So I did this when I could, and I must say that I'm perfectly prepared to discuss anything you want to about China. I think I'm very much up to date on them and the kind of challenges they pose to us in the future.

That's the reason I was interested in being on the commission, because I think they are an important country to our future.

WALLACE: Senator, a couple of minutes left. As the Iowa caucuses draw close, any second thoughts that perhaps you should have gotten into this race earlier? Any regrets?

THOMPSON: Not really, Chris. I've always had this notion that I could get in about the same time people traditionally do and that I could do it without spending the millions of dollars that other people have spent, and that if I and my views were in sync in the American people, that it would work out and that we could have a wonderful opportunity to do some things together, and that if it wasn't in the cards, it wouldn't have anything to do with whether or not I visited Ames five or eight times. It's just the way I look at things.

Now, after this is over with, you know, one of us can second- guess the other. We don't know who it's going to be yet, and we'll see. But I feel very comfortable with the decisions that we made and the way we're going about it, and it looks like the timing is pretty good.

There's still a lot of undecided voters after people having spent all of this money and all this time and effort, and running for years in some cases, and they're open to the message that we have. They're open to me, learning more about me.

And timing is everything. This is the way we campaigned in Tennessee. We went from 20 points down to 20 points ahead on election night, and I was able to win two races in Tennessee by 20-point margins in a state that Bill Clinton carried twice.

So I like to think I know a little bit about what I'm doing. This is a different stage and a different arena, and I understand all the experts feel differently about it. They may be right. But we'll see. Won't take us long to see now.

WALLACE: Well, that's right. We'll see how the world turns on Thursday night.

Senator Thompson, we want to thank you so much for talking with us. And we'll see you there...